In the prior art, it is known to have louvered dampers 100 as shown in FIG. 13 with rotatable movable blades 102 in FIG. 13. These dampers are amounted in the wall 104 in FIG. 13 of a building to exhaust the air from the interior of the building or to draw air into the interior of the building. Typically, these dampers have a manual motorized actuating device to open the laterally disposed slats or blades of the damper in order to permit the intake or outflow of air. Further, there could have been a motor 106FIG. 13 mounted on the interior of the building driving a fan proximate to the rear of the damper to draw in air or to blow air out. In such a case, it was common to have a bell mouthed shroud 108FIG. 13 juxtaposed between the blades of the fan and the rear 110FIG. 13 of the damper. A portion of the bell mouth was positioned in very close proximity to the tips 114FIG. 13 of the blades in order to provide a partial seal and thereby provide pressurization. The same was true of the configuration for air intake fans. In each case, the motors were fixedly mounted with respect to the bell mouthed damper box shroud 108.